Process of treating vanadium ores and solutions



Aug. 24 1926. 1 1,597,216

w. E. sToKEs PROCESS OF TREATING VANADIUM ORES AND SOLUTIONS Filed Jan. 19. 1921 2 Sheets-Sheet 1 (Salaam, QfSQzzzbZe www@ Decomposalead Veranda/te (Reage'raN/Zr//6Z) Www/ggf;

w. E. 'sToKEs PROCESS OF TREATING VANADIUM ORES AND` SOLUTIONS Aug. 24 192e. 1,597,216

Filed Jan. 19. 1921 2 Sheets-Sheet 2 Patented Aug.' 24, 1926.

UNIT-ED sfiii'ras A 1,591,216 PATENT OFFICE.

WILLIAM E. sToirEs, or aocxviLLE CENTER, NEw Yoiix, nssieNoa To UNITED sTATEs rijwcEssEs, iNo., or NEW Yoan, N. Y., a coaroisATIoN or NEW Yoiix.

PROCESS F TBEATING VANADIUM OBES AN D SOLUTIONS.

Application `lled January 19, 1921. Serial No. 438,485,

This invention relates to the recovery of vanadium, and aims to provide improvements therein.

The present invention provides a process,

and sub-processes, wherein there is a ood recovery of the vanadium constituent rom.-

ores or solutions, the recovery being better than that derived by previously known processes. The invention also enter the process, only incidental replace-- '20 ments of said 4reagents for working losses being re uired.

Accor ing to the presentl invention, the vanadium ore isleached, to dissolve the vanadium com ound. In the case of re fractory ores, the ores may be subjected to a preliminary roast or fusion with a transposing agent, such as sodium chloride or carbonate, according to any well-known method.

The solutions thus obtained are usually very dilute, usuall not containing more Athan one per cent o vanadium, and usually containing a considerably less percenta e of vanadium. Only a limited recovery oy the vanadium constituent from such dilute 'solutions is obtainedY by the usual methods now in use. As the recovery Vof vanadium is no w usually carried out, the practice is to concentrate the solution by heat evaporation.

40 In the evaporation of large quantities of solution, the fuel useds a large item of expense.`

In order to v avoid this large use of fuel, if-according to the present invention, use 'is made of a reagent which will preci itate the vanadium constituent in a form which is extremely insoluble in the solution.' Soluble salts, such as the chlorides, acetates or nitrates of barium, lead, copper, or iron are added to form a vanadate of low solubility, and, hence, precipitate to an extent which ractically completely exhausts the solution. lnder the expression vanadate is to be understood any of the vanadatcs which the rovides' for '.10 the recovery of vanadium sa ts of great metallic or base-forming element is capable of forming with the vanadium compound.

The precipitate is separated from the solu- I tion in a suitable manner, for example, by filtration. y

After the precipitated vanadate has been separated from the mass of leach water, it is then decomposed; and the separation, as a precipitate, is effected, of either the vanadic *y oxid (V205), or of the base-forming element united with the vanadate. 65

A. The insoluble vanadate is treated with an acid. For example,.a solution of hydrochloric acid may bel added to the vanadate, the hydrochloric acid being in equivalenti, proportion to the vanadate. The acid and vanadate then have added thereto a salt in the presence o which the vanadate readily dissolves, and, in the solution of which thel resulting vanadic oxid has a slight solubility, such, for example, as an ammonium, sodium, calcium, or magnesium chloride or acetate, ammonium chloride being at present considered a preferable salt for this purpose. In an acid ammonium chloride solution, the insoluble vanadate readily dissociates, and the vanadic oxid which is formed preci itates, and vcan be separated in any suitable manner, by filtration for example. The lead l chloride, for example, resultin from the action of the acid upon the inso uble vanadate, runs off in the filtrate, and the liltrate may be used again in the process. For example, the ltrate may be acidiiied, thus precipitating the lead chloride, which can be used again toprecipitate the vanadium constituent from the solution resulting from leaching the ore, asv heretoforel explained. The ammonium chloride could be used again in the preceding step, wherein thev dissociation of the lead vanadate is effected, and the liquid could be returned to the original solution of soluble vanadates. Any losses of vanadic oxidwhich might result from in\ complete precipitation would be recovered,

inasmuch as the vanadium constituent running oif into the filtrate resulting from the dissociation step would be returned to the solution of the soluble vanadate obtained by. the leaching step.

B. If, however, an excess of acid be added to the insoluble vanadate, the vanadic oxid resulting from the dissociation will not precipitate, but will remain m solution, andthe treated with ammonia. When the acidity the vanadic oxid is insoluble,

has been reduced, the vanadic oxid will precipitate, and thevanadic oxid may be removed from the solution by filtration, and the filtrate, containing the ammonium salt, may be used again in connection with the acid used for dissociating the insoluble vanadate, or for washing the precipitated vanadic oxid.

The vanadic oxid thusprecipitated may be used as the final product, or it may be purified. l

A. To purify the vanadic oxid, it is preferably washed with water containing an ammonium salt, and thereafter heated to volatilize the ammonium salt contained in the absorbed water. l.

B. Or, the impure 'vanadic oxid may be dissolved'in an acid which will dissolve the vanadic oxid, as, for example, hydrochloric or sulphurlc, and alcohol or other liquid in which the impurities are insoluble and the dissolved vanadic oxid is soluble. IThe acid will act on any barium, calcium or lead salts which may be mixed with the vanadic oxid, and form insoluble salts, which will be completely precipitated in the alcohol, and can be separated by filtration. After the solution is filtered, to remove the foreign salts, it is treated with ammonia, or an ammonia solution, to neutralize the acid` in which solution of the ammonium salt of the acid,

andprecipitates. The precipitated vanadic oxid may be removed by filtration, the filtrate distilled to recover alcohol, and the ammonium salt remaining in the solution, together with the separated alcohol, may be used again in the process, for example, the ammonium salt may be used as one of the reagents for dissociating the insoluble vanadate, described above. The vanadic oxid is then preferably heated, to volatilize the ammonium salt.

he accompanying drawings show two specific examples of the present process. Y The followingjs a description of a particular example of the process: A solution of vanadium salt is obtained, by leaching for example. The solution may be neutral, or alkaline, or acid, though a neutril or alkaline conditionv is to bepreerre Lead chloride is then added to the leach solution. which acts upon the soluble vanadate to form lead vanadate. The lea-d vanadate, being very insoluble, is precipitated. The lead chloride may be used in excess, and goo'd results are obtained by using 5 parts by weight of.lead chloride to one part of vanadic oxid (V205). The lead vanadate settles easily, and it may be removed from the spent leach water by filtration. The precipitated lead vanadate is then preferably washed, to remove impurities, and the lead vanadate is then one of high purity.

In order to recover the vanadium 'in the form of vanadic oxid, the lead vanadate is mixed with water, and sufficient hydrochloric acid, to form lead chloride with the lead of the lead vanadate. To this solution, either simultaneously or separately, with the addition ofthe hydrochloric acid, there is added ammonium chloride. Enough ammonium chloride is added to make a saturated solution. 85

In practice, a solution of ammonium chloride is preferably made separately from the acid solution containing theJ decomposed lead vanadate, and the acid solution containing the decomposed lead vanadate is added slowly, with stirring, to the ammonium chloride solution. The ammonium chloride solution is preferably maintained at boiling temperature. The boiling is continued until the lead '95 vanadate is entirely decomposed and the vanadic oxid precipitated, the vanadic oxid being practically insoluble in the solution of ammonium chloride.

The precipitated vanadic oxid is then separated from the solution, preferably by filtration, and the filtration is preferably carried out While hot, to prevent lead chloride crystallizing out and contaminating the vanadic oxid.

The .precipitate (V205) is then preferably 105 washed with water containing ammonium chloride, and the vanadic oxid is thereafter heated, to drive off the water and ammonium chloride, the vanadic oxid which is left then being of high purity.

The filtrate, containing ammonium chloride and lead chloride, is preserved and preferably acidified, to precipitate the lead chloride, which is returned to the process, being used tov again precipitate the lead vanadate. The ammonium chloride may also be used again in the step wherein the lead vanadate is dissociated.

As an alternative method of purifying the precipitated vanadic oxid, the vanadic oxid may be dissolved in hydrochloric acld, together with alcohol. The hydrochloric acid will act upon any lead contained 1n the vanadic.I oxid, and convert it into lead chlo-f4 ride, which lead chloride, being insoluble in 125 alcohol, will precipitate in the solution, and may be separated therefrom by filtration. The filtrate is then treated with a solution of ammonia, to neutralize it, and then heated to distill off the alcohol. The vanadicoxid 130 precipitates in the presence of the ammonium salt solution, and 1s separated by filtration. The precipitated vanadic oxid is then heated to volatillze .the ammonium chloride, the vanadic oxid which is left being of high purity.

The filtrate containin the ammonium salt is retained and returned to the process; for example, to the step wherein the lead vanadate 1s dissociated, or sodium hydroxid may be added and the solution heated to convert the ammonium chlorideintoammonium hydroxid and ammonia evolved, and utilized to neutralize the acid in the ste succeeding the step where the acid and alco ol are used for purifying the vanadic oxid.

The invention is not limited to the specific procedure herein described, and steps and i sub-combinations of steps may be employed,

separately from the comilete process described. The inventive i expression in a variety of specific procedures.

What is claimed is:-

1. In a process of recovering vanadium which conslsts in adding a lead salt to a leach solution containing a soluble vanadium compound to preci itate lead vanavdate, separating the precipltate from the solueas may receive,

tion, decomposing the precipitate bi an excess 'of acid in a salt solution in w ich the resultin lead sa t is insoluble, separating out lthe lead salt, and treating the solution to reduce its acidity to precipitate the vanadium oxid.

2.l In a process of recovering vanadium, decomposin an insoluble vanadate by an acid in a sa tsolution in which the resultant vanadic oxid is insoluble, separating the vanadic oxid from the solution, dissolving the vanadic oxid in ,an acid in the presence of an organic li uid, separating the resulting precipitates rom the solution and neutralizing the acid solution to precipitate the vanadic oxid.

vanadium oxid is soluble and the 3. In a processof recovering vanadium,

dissolving 1n an acid in the presence of an. organic iquid vanadic oxid contaminated with salts formed by the base forming element of the vanadate from which the vanadic oxid was obtained, separating the liquid from the resulting precipitates, and neutralizing the acid in the solution to precipitate the vanadic oxid.

In witness whereof, IV have hereunto signedmy name.

WILLIAME. sToKEs. 

